Not sure how you came to that determination when the link you posted clearly states otherwise.
If you read beyond the heading "Lounge access at Hamad International Airport," you get this "Enjoy lounge access2 at select airports around the world, and Business Class lounges at select airports, regardless of your class of travel."
Typically access is granted at contract lounges (other than in Doha) and has been a benefit for a long time for the passenger only. No guest access.